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Dan Neeson January 27th, 2010 10:15 AM

Canon 7D Noise and Pixilation Issue - Please help
 
Hi Guys,
I was wondering if someone could help me...
I have a canon 7d and i just can't get any good low light pictures without a load of noise/ pixilation. I was wondering if you could please take a look at my settings/ videos and see if there is anything you can recommend?

Here are some videos where you can see noise on the left side of the subject's head.
YouTube - New Noise Video - desat - Canon 7d.



YouTube - New Noise Video - Canon 7d



(these were exported from AF CS3 as mp4 - so things are a bit blurred, but you can see what i mean from the next vid)

and you can really see it here:
YouTube - Canon 7d - noisy footage issue (desatured) (look at the above right of the subject's head - where the white fades to black... it's like a pixil ant party up there!)

Here are some stills that i extracted from other videos:
http://i974.photobucket.com/albums/a...non7DNoise.jpg

http://i974.photobucket.com/albums/a...oiseColour.jpg

Here are my settings:




Here is the set up I am using:

Canon 7d Body

Lens - Canon 50mm F1.8

Aperture: f1.8

Shutter Speed: 1/50

ISO: 200

24fps 1920x1080HD PAL

White Balance: 5000k (matched to light source)



Light Source 15w CFL Fluorescent lamp, (equivalent to about 60w - 75w incandescent) placed approx 1m away from subject's face.

Camera Settings:

User Def. 1

Sharpness = 0

Contrast = Absolute

Saturation = 2 clicks negative

Color Tone = 0 (default)



Highlight Tone Priority = Enabled

ISO Expansion = Enabled



Converting footage from Canon format to Avid ADxHD codec using MpegStreamClip and editing in After Effects CS3.

All comments are very much appreciated

Thx :)

David Chapman January 27th, 2010 12:50 PM

I don't have experience with Avid formats, but I will say that I would need to see shots of the original to compare noise. The pixelation I see is from YouTube's h.264 compression for web and not related to what the camera shot. If you compress the footage enough with a low bit rate, you will see a lot of blockiness.

I also noticed that some of your uploads were a wrong aspect ratio.

Dan Neeson January 27th, 2010 06:26 PM

New Video Example
 
Thanks Dave,
Here is an uncompressed video that i uploaded straight from the flash card.
Any Thoughts?

YouTube - Uncompressed Video - Noise/ Pixilation Issue

Perrone Ford January 27th, 2010 07:09 PM

Yep....

Noise = insufficient light
Pixellation = weak h.264 codec in the 7D.

Shoot the same scene at ISO 640 and see what you get.

Daniel Browning January 27th, 2010 07:19 PM

Quote:

Originally Posted by Dan Neeson (Post 1477931)
Highlight Tone Priority = Enabled

One way to reduce noise is to let your highlights blow out by disabling HTP. Personally, I'd rather have the noise. :)

Perrone Ford January 27th, 2010 07:24 PM

Quote:

Originally Posted by Daniel Browning (Post 1478193)
One way to reduce noise is to let your highlights blow out by disabling HTP. Personally, I'd rather have the noise. :)

Why? Reduce latitude in the shot and nothing needs to blow out.

Daniel Browning January 27th, 2010 07:32 PM

Quote:

Originally Posted by Perrone Ford (Post 1478195)
Why? Reduce latitude in the shot and nothing needs to blow out.

Because reducing latitude in the shot is not always possible or desired. For example, I don't normally carry a nuclear warhead bright enough to reduce the contrast in mountain landscapes. ;) Other times, I do have the nuke with me, but I just don't want to change the lighting because I like having highlights that are four (not three) stops above mid gray before clipping.

Perrone Ford January 27th, 2010 07:39 PM

Quote:

Originally Posted by Daniel Browning (Post 1478199)
Because reducing latitude in the shot is not always possible or desired. For example, I don't normally carry a nuclear warhead bright enough to reduce the contrast in mountain landscapes. ;) Other times, I do have the nuke with me, but I just don't want to change the lighting because I like having highlights that are four (not three) stops above mid gray before clipping.

I didn't mean in all situations.. I mean in THIS situation.

Ands sounds to me like you need to upgrade your arsenal to some include some smart, tactical nukes... Just to even things out a bit. Or you need a RED. :)

Daniel Browning January 27th, 2010 07:46 PM

Quote:

Originally Posted by Perrone Ford (Post 1478203)
I didn't mean in all situations.. I mean in THIS situation.

I see now, thanks. Yes, he may want to do that.

Quote:

Originally Posted by Perrone Ford (Post 1478203)
Ands sounds to me like you need to upgrade your arsenal to some include some smart, tactical nukes... Just to even things out a bit. Or you need a RED. :)

Or both. That's how they made Book of Eli. :)

Dan Neeson January 28th, 2010 08:26 AM

Thanks everyone - i'll play around and see how it goes.
dn


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